The present invention relates to powders comprised of thermotropic liquid crystal polymer particulates and a method of production of such particulates.
The excellent chemical resistance and high temperature stability of thermotropic liquid crystal polymers can desirably be put to good use in protective coatings. See, for example, commonly-assigned U.S. Pat. Nos. 4,238,598 and 4,238,599. However, as a class, these materials are not easily ground into a fine powder suitable for use in such coatings. The high polymeric orientation which is so prevalent in these materials, irrespective of the manner of processing, leads to fragments of a very high aspect ratio which tend to clump and tangle rather than flow. Cryogenic grinding, which is conventionally used to produce powders of thermoplastic materials, is costly. Furthermore, the surprising toughness which thermotropic liquid crystal polymers possess at cryogenic temperatures make this type of grinding exceedingly slow.